This inequality contributed to the Occupy protests a couple of years ago, and it’s fueling the fast-food workers’ strikes now. And it is exemplified by fantastically profitable companies like McDonald’s choosing to pay employees so little that they have to live in poverty.

Contributing to this inequality is a new religion of shareholder value that has come to be defined only by “today’s stock price” and not by many other less-visible attributes that build long-term economic value.

Like many religions, the “shareholder value” religion started well: In the 1980s, American companies were bloated and lethargic, and senior management pay was so detached from performance that shareholders were an afterthought.

But now the pendulum has swung too far the other way. Now, it’s all about stock performance–to the point where even good companies are now quietly shafting other constituencies that should benefit from their existence.

Most notably: Rank and file employees.

Great companies in a healthy and balanced economy don’t view employees as “costs.” They don’t try to pay them “as little as they have to to keep them from quitting.” They view their employees as the extremely valuable assets they are (or should be). Most importantly, they share their wealth with them.

One of the big problems in the U.S. economy is that America’s biggest companies are no longer sharing their wealth with rank and file employees.

Consider the following two charts:

1) Corporate profit margins are at all-time high. Companies are making more per dollar of sales than they ever have before.

2) Wages as a per cent of the economy are at an all-time low. This is closely related to the chart above. One reason companies are so profitable is that they’re paying employees less than they ever have before.

When presented with these charts, many people invoke one of two arguments. First, technology is making employees irrelevant. Second, low-skill jobs command low pay.

Both of these arguments miss key points: Technology has been making some jobs obsolete for 200+ years now, but it is only recently that corporate profit margins have gone through the roof. Just because you can pay full-time employees so little that they’re below the poverty line doesn’t mean you should–especially when retention is often a problem and your profit margin is extraordinarily high.

More broadly, this narrow view of “shareholder value” has led companies to put “maximizing profits” ahead of another critical priority in a healthy economy: Investing in human and physical capital and future growth.

If American companies were willing to trade off some of their current profits to make investments in wage increases and hiring, American workers would have more money to spend. And as American workers spent more money, the economy would begin to grow more quickly again. And the growing economy would help the companies begin to grow more quickly again. And so on.

And, ultimately, as with any ecosystem that gets out of whack, it’s bad for the whole ecosystem.

So, for the sake of the economy, we have to fix this problem.

Ideally, we would fix it by getting companies to voluntarily share more of their wealth with their employees. But the “shareholder value” religion has now been so thoroughly embraced that any suggestion of voluntary sharing is viewed as heresy.

(You’ve heard all the responses: “The only duty of a company is to produce the highest possible return for its owners!” “If employees want to make more money, they should go start their own companies!” Etc. Beyond basic fairness and the team spirit of we’re-all-in-this-together, what these responses lack is any appreciation of the value of personal loyalty, retention, respect, and pride in the workforce. People love working for companies that treat them well. And they’ll go to the mat for them.)

So if companies can’t be persuaded to do this on their own, maybe it’s time to do one of two things. First, as my colleague Josh Barro suggests, increase the minimum wage. And/or second, rethink our view of labour unions.

Although correlation is not causation, the chart below suggests that labour unions might be able to help induce companies to share their wealth, at least in some industries.

The chart shows the correlation between the share of the national income going to the to 10% of earners with membership in labour unions. What it suggests is that, as unions have declined, income inequality has soared.